i just got the blue ribbon 12" one from window cleaning wharehouse.
i'm pleased with it i'm pretty quick anyway with squeegee.
If your pretty good downstairs with 2 handed technique mop and squeegee, then i there's only a few secs between wag and normal squeegee. imo
But if your trad then it must be quicker off ladder using wagtail,
only thing is wagtail pad dosen't hold much water, so you'd need small water bottle in your pouch or keep dipping in bucket.
I used on a couple of indoor jobs and found very good.
I think the great thing for wagtail is indoor pole work, or even outdoor pole work shops.
I am wfp and use wagtail for odd windows, the blue ribbon wagtail fits in bucket on belt thanks lee